Hi everyone,

My engine is going in for it's internal upgrades soo, it's an L31 OE roller vortec. It's currently carb'd. My builder is anticipating it laying out around 430 HP and 400 Torque after all the internals go in (including a forged crank, rods, flattop pistons, and an XFI cam from comp cams) running between 10 and 10.5:1 compression.

He's of course going to do all the requisite work for the heads to handle the lift and clean up the bowls and ports and whatnot. Now he's not a FI guy, pretty much everything he does is carb'd, so that's why I'm here.

So my plan is to get the SDPC vortec baseplate and egr kit, an 85-92 Camaro TPI upper, and the runners from here http://www.azspeed-marine.com/19latuinru.html (or something very similiar).

Then top it off with EFIConnections 24x coil near plug setup and drive by wire throttle (I was going to go with theri 58mm unit that they sell), along with the rest of their kit and TPI wiring harness.

My concerns are:
Runners - this engine is going in a light car, so the torque is very noticable as it is. I'd like to see the horsepower range move up a bit. And I see that some runners are made for different years, and saw that it might be because some years were MAF and some were MAP, and that runners for one system wont' work on the other? So are the runners I posted the best choice for my setup? Or should I try to track down the SLP runners? Or something else? (I was going to buy this off of ebay, keep the plenum and resell the rest - http://cgi.ebay.com/ebaymotors/85-92...=p4506.c0.m245 )

Upper intake plenum - Opening it up for the 58mm throttle body and for larger runners isn't an issue, are there other restrictions to this piece that I should take into consideration and think about getting something different? If I have to go with something different, I was thinking about getting one of FIRSTs intakes that have the "side port" on them (the engine sits transverse in the car).

Anything else I'm missing or not thinking of? Again, the wiring harness and computer and drive-by throttle will be supplied by EFI, and I just need to get all the sensors and get my headers modified for them (and the egr).

Thanks guys!

 

The starting point is the plenum. If you have an 89-92 plenum, you need the 89-92 runners because they did away with airflow to the 9th injector in 1989. If you have an 85-88 plenum, you'll need to use the 85-88 runners. All TPI intake manifolds are interchangeable with all TPI runners.

The emissions requirement and Vortec heads pretty much force you into using the TPI manifold.

Here's your challenge
The LS1 PCM cannot control the TPI type EGR solenoid. You will need to use a linear type EGR valve with the LS1 PCM. The linear type EGR valve will not bolt to the TPI lower intake manifold. I'm not sure what to suggest for fabrication.

 

Hey Mike,

Thanks for the heads up - at this rate, I'm going to stop reading things and just email you (even more). lol

Well, I was going to get that SD baseplate because I've heard it's got some great flow, besides having the EGR and working with vortec.

Sadly, my lack of knowledge here keeps me from having any ideas for what to do about the EGR, since I don't know what the SDPC egr provision looks like... or the linear type egr. Time to do some more searching!

Outside of that bit of bad news, thank you for the info on making sure I get all the right TPI parts!! Back to the searching on that stuff. lol

 

No problem. The latest intake manifold on my S10 is the Vortec lower TPI, SLP runners, and ported plenum. I would rather still have the RamJet 350 intake on the engine (no EGR provision), but prototyping the new throttle bodies required a TPI type manifold.



http://www.rockauto.com is a great place to look up images of parts. You're simply looking for an LS1 EGR valve...try model year 2000.

 

Okay - ignorant question time... it *Seems* like you're saying your current setup has an EGR, but you'd rather have the Ramjet which did not have an EGR. From the picture, you obviously have the CnP setup going on...

So, how did you pull it off? Or is my presumption of your existing setup having an EGR totally incorrect?

 

No EGR. All that was required for emissions was a canister purge (not even electronic).

The only hope I see for EGR a TPIS MiniRam and a custom EGR adapter plate. See their website for the early EGR provision. But the MiniRam does not fit Vortec heads.

 

Here is what I'm going to do about the EGR since I only care that it passes a visual emissions inspection which will likely be conducted by a hasty amateur:

Just basically make an EGR block off out of the EGR valve. Clog the hole with something and make it a non-functional EGR valve that works like a block-off plate. Run a piece of vacuum hose to nowhere. They will never know the difference and unlikely that your car will be so close to failing that this will fail it. You can always detune the engine a little for emissions and then slap the good tune back on it after they sniff your pipes if lack of EGR is actually causing you to fail the sniff portion of the test. The tester is unlikely to know that an LS1 0411 PCM can't control the old EGR valve.

If you wanted to get fancy you could figure something out with studs and nuts and be able to remove the EGR valve after the emissions test and regain a little visual appeal.

 

Thanks for the clarification Mike!

James - thankfully my car doesn't undergo the sniff test anymore, but for whatever reason the "safety inspection" that it still has to undergo states that they are supposed to check for all factory emissions control equipment or equivilants. So that might be the only way I have to go.

So back to the rest of the TPI - there's a bunch of complete systems (most minus the harness, which is fine) on ebay right now, some have AFPR, some don't.

so now I know to avoid the systems that have the "ninth" injector. Outside of that, any tips for what I should lok for when I get it, or what a "fair price" for the units are?

Or would it be cheaper/easier to just buy any plenum (that is the right name for the upper intake, isn't it?) and fuel rails seperately?

** EDIT ** Mike -- it hasn't been mentioned so I'm guessing it doesn't matter, but better ask then not. Does it matter if the TPI system I get is MAP or MAF when it comes to your CnP system?

 

Unfortunately, the SDPC does NOT flow well at all, contrary to what you've been lead to beleive. It was recently tested, and the ONLY manifold it outflowed was the stock base, and it wasn't by a lot IIRC. Beleive me, I'm not happy about that either. I really wanted to use it. Still may, bu that's another conversation.

...if you're looking for upwards or 430hp, you really need to be looking away from the long tube runner set up, and look more at the mini-ram, stealth ram, super ram set ups.

 

Hey Abubaca,

Thanks for the information - that's sad to hear... I was hoping that with a little porting and shorter/wider runners I'd overcome any breathing limitations.

I guess I'll need to start checking other options then, and as I pick things out, run them by Mike and Co. over at EFI connections, see if they see any issues about rigging up their system... not to mention figuring out which one will be easiest to have a visual/non-functioning EGR on there - you know, for show.

I'll start checking into the ones you recommended - I had read up on the Accel Super Ram before... and that it was designed by ... someone who's last name starts with an 'L'. lol. But from reviews I read, said that getting the thing installed was a real PITA.

Any other first hand experience/recommendations from anyone?

** EDIT ** - Okay, first thing I started looking at is the Stealth Ram ( http://www.summitracing.com/parts/WND-7542/?image=large ). And I have a bizarre question - on something like that, can the plenum be turned around? It sorta looks like it could just flip around with out an issue - and with the Coil Near Plug stuff the distributor will be much 'shorter', so it shouldn't be in the way, would it?

Otherwise, it seems like a pretty inexpensive way to go, compared to looking at the asking prices for TPI setups... the Stealth Ram is the cost of just what the aftermarket runners I was looking at cost. (and then just need to do something about that EGR issue, but that's secondary at this point.)

 

First off, I'm not trying to disagree with anything Mike has to say, as he's a lot wiser than I!!! ...second, I'm not saying the SDPC is bad, OR that you can't make power.

....but I think it's got it's place in the world of hot rodding, and hi powered set ups are NOT it's place. It's a little better than stock, which is good, AND it allows you to use affordable GM Vortec heads. Overall, it's VERY good option for a great "bang for your buck" build. Whether or not it's for YOU and YOUR goals is up to you.

Super quick rundown of the other manifolds: The Super Ram (John Lingenfelter) is a proven winner, but as you've read, can be a PITA. The Miniram is arguably overpriced, but it'll support a ton of power. LOTS of proven high powered builds with that intake. The holley stealth ram is a great choice because it's so affordable, and another proven performer. I'm not sure if it'll flow quite as much as the others, but people are gettin' lot's of power out of them. Best advice I can give you is not to take MY advice, but read, read, read. ...then of course you have the ramjet. I don't know a lot about it since obviously not a lot of people use it. Mike seems to have worked out some of the issues, and that might be a viable option for ya. I'd talk to him.

Anyhow, I'm really not trying to tell you to go one way or another. I just saw you mention around 430 hp, and say that you heard the SDPC intake flowed real well, and I just thought I'd at the very least, suggest you double check your info, and do a little more reading. I wish the SDPC would support those numbers, and I'd be thrilled if I were wrong, but from what I've read.....well, like I said, just read read read!!!!!

 

If you're looking for a bit more horsepower, you could also step up to the John Lingenfelter designed ACCEL SuperRam intake. The SuperRam runners are shorter than the TPI runners to increase top-end horsepower while sacrificing little power below peak torque. We've had excellent results with this manifold, and on a 420ci small-block, we've made as much as 525 hp and 540 lb-ft of torque with this intake."

Full article is here: http://www.chevyhiperformance.com/te...ead/index.html


The other option I was considering (if I can find someone to do the work) is convert the marine intake for the vortec heads. There's another forum with a huge thread on how to do it, and a where to get the intake and who to buy the parts kit from, but since I was having an issue finding someone who could do the needed mods to it (and I don't trust myself to do it right), I let that fall by the wayside.

So I guess I'll start revising my searches using the intake suggestions you made, and see what kind of power guys are laying down and where that curve is.

I appreciate all the feedback!

 

What exactly are your goals? ...what parts do you already have, if any? I was looking at Mike's 24x swap/mod/upgrade as well, and as far as I can tell, just about any multiport FI manifold would work. Mike could tell you for sure. Big thing now is to match your budget and goals with a cam/head/intake set-up...

Are you stuck on Vortech heads?

 

OK, I re-read your first post. L31 roller and heads, transverse mounted, "light" car. ...Fiero?????

Again, not sure what your goals are, but that'll be a beast, even with a LOT less power than you're thinking. The long tube set up is really gonna over torque what you wanna do I think.

 

Hey again Abubaca!

Yes, you are correct, it's a Fiero GT that the engine in it's stock state is currently sitting in.

Goals - I don't have a set HP/Torque in mind anymore, the main reason is I've read alot of threads at different places of people who were disappointed with the results (didn't feel they got enough bang for their buck). **edit** the numbers I've listed, as I've stated, are what my builder anticipates getting with my carb and the parts I've picked out. If I hit it, great! If not... oh well. lol **end edit**

My plan for this car, is building up the engines internals so I'll have durability and longevity (forged crank, forged pistons, forged rods rated for 700hp, etc), get the heads optimized (the builder does alot of truck/hotrods, lots of experience with Vortec heads, and has figured out how far he can work them before the performance actually starts to fall) and then find the most efficient way to convert it to fuel injection and do the EFI conversion.

I'll be honest, I'm not knowledgeable enough to know what performance improvements I'll see with the 24x setup - I want to to do it for one primary reason, and one very distant secondary reason:
1) Unique. I'm building a (somewhat) unique car as it is, I might as well do what I can for it to really stand out (excluding body work and stuff, I mean just from a mechanical standpoint).

2) if I'm REALLY lucky, with the "shorter" distributor/cap thingie that the 24x uses, and if I pick the right intake, I can flip it around so the throttlebody will be facing the driver side (instead of passenger as it would now with the way the engine sits) - this will let me use the stock fresh/cold air intake that's on the car.

Because the car is light (under 3000 lbs with me in it), I'm willing to look into options that could reduce torque, but afford me higher horsepower, or at least broadening or moving my power range up a bit.

And then lastly I'm planning on running 150 shot of nitrous on it. But that improvement will likely be after I get the transmission work done.

Oh, and I am running headers right now - though I dont know the size of them, didn't measure the diameter, and I don't know what length constitutes a short header versus full.

My budget for the fuel injection stuff (including the CnP stuff) is floating around 2000-2500. From doing alot of "ballparking" it seems like I should be able to get everything I need for the carb-to-EFI conversion (*maybe* with the exclusion of some sensors - prices for those seem to be all over the place) for about that.

If anything I've stated is wrong, please let me know! The downside to the internet... there's alot of great info, and just as much BS.